Yamaha RS90K, Service Manual

Page: 106 / 841

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INSP
ADJ
AIR BLEEDING (HYDRAULIC BRAKE SYSTEM)
AIR BLEEDING (HYDRAULIC BRAKE
SYSTEM)
WARNING
Bleed the brake system in the following cases:
• The system has been disassembled.
• A brake hose is loosened or removed.
• The brake fluid has been very low.
• Brake operation is faulty.
If the brake system is not properly bled a loss of
braking performance may occur.
1. Bleed:
• Brake system
Air bleeding steps:
a. Fill the brake master cylinder reservoir with the
proper brake fluid.
b. Install the diaphragm. Be careful not to spill any
fluid or allow the brake master cylinder reservoir
to overflow.
c. Connect clear plastic hoses 1 tightly to the
brake caliper bleed screws
2
.
d. Place the other ends of the hoses in a con-
tainer.
e. Slowly apply the brake lever several times.
f. Pull the lever in, then hold the lever in position.
g. Loosen the bleed screws and allow the brake
lever to travel towards its limit.
h. Tighten the bleed screws when the brake lever
limit has been reached, then release the lever.
i. Repeat steps (e) to (h) until all of the air bubbles
have disappeared from the fluid.
j. Tighten the bleed screws.
NOTE:
If bleeding is difficult, it may be necessary to let the
brake fluid settle for a few hours.
Repeat the bleeding procedure when the tiny bub-
bles in the system have disappeared.
k. Add brake fluid to the proper level.
Refer to “BRAKE FLUID LEVEL INSPECTION”.
WARNING
After bleeding the brake system, check the
brake operation.
T
R
.
.
Bleed screw:
6 Nm (0.6 m · kg, 4.3 ft · lb)